Reconfigurable passive filter

A passive filter for connection between an AC source and a load, the passive filter comprising:

• a trap circuit, comprising an inductor in series with a capacitor, the trap circuit having at least two terminals;
• a line reactor connected between the AC source and the load, the line reactor having at least an input terminal, an output terminal and a tap terminal;
• a switch for selectively connecting at least one of the line reactor terminals to the load based on the voltage distortion experienced by the AC source.

A three-phase passive filter for connection between a three-phase AC source and a three-phase load, the passive filter comprising:

• a trap circuit, comprising a three-phase inductor in combination with a three-phase capacitor, the trap circuit having at least three terminals;
• a three-phase line reactor connected between the AC source and the load, the line reactor having at least an input terminal, an output terminal and a tap terminal for each of the three phases;
• a three-phase switch for selectively connecting at least one of the trap circuit terminals within each phase to a selected one of the line reactor terminals within that respective phase.